HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

[lmcancu]

Hi I have a HP DV6-2064CA laptop. My son had dropped it a few months ago, and the fan needed to be replaced. I replaced the fan and put in new thermal pastes, SSD drive, etc. He does alot of gaming on it, and reached CPU temperatures over 80. recently. It stated freezing on him, and the hard disk crashed. The problem is that it will boot up ok, but if you power it down and then try to boot it up again it will shut down automatically. So I took it apart, re-applied the thermal paste, checked for any obvious issues or burns. Put it back together without the SSD drive. It will boot up into BIOS fine, I can run tests and it can reach 80 degrees no problem. But if I power it down, and power it back it will automatically shut down and not even go into the BIOS screen. I tested it more, and it looks not even to be heat related. If I power it up for a few seconds, then power it down. Power it back up immediately, it will power down automatically. If I wait a few minutes and power it back up it runs fine until I power it down again. Where do I start looking? CPU? Motherboard? Power button? I tried this on both battery and power brick.

Thanks for any help

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

Just performed some burn-in tests booted from a parted magic CD and reached temperatures of 86 C. The system is still up with no issues. So its ok once it boots up. The problem is I guess a "warm" boot. Power button issue?

This is the part? Could this cause the weird behavior? How would I troubleshoot this part?
http://www.ebay.com/itm/HP-DV6-1000-...item3cc8695be1

[dj_ricoh]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

nee!
thats not the problem the problem is cold joint ~

when he drop it down(i dont think its true; rage ) was hot and maybe something move inside.

cook the board!

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

Not sure its a cold joint. This happens even if I shutdown the laptop if its been on only for a few seconds. i.e. turn on the laptop, goes into BIOS, wait 3 seconds, shut down. If I now turn it on it powers down right away. If I remove the power, remove the power button piece, press it a few times, and them reconnect, and power up again it comes back up 8 times out of 10. I'm thinking the power button logic is in a funny state. I think the power button circuit has some very small caps in it, so maybe there is some memory that's not cleared properly.

[dj_ricoh]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

power it up with a tweezer or a resistor direct on the connector!

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

Does anyone have a schematic for a HP DV6-2064CA laptop with AMD chipset? It's a DV6-2000 series

[ala_borbe]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

need full motherboard code

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

Thanks the motherboard code is DAUT1AMB6E0 Rev. E. I also found this link which suggests a solution for the same symptoms I have. Does anyone know where PQ41 is?

Thanks

http://www.elvikom.pl/hp-dv6-motherb...ff-t32036.html

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

I found Pq41 on the motherboard. It gets very hot at startup " can't leave finger on it for more than a couple of seconds. Does anyone know if this is normal. Anyway to test to see if the mosfet is ok?

[ala_borbe]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

it should be one of those UT1/2 - UT12

[reaper57]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

You should be able to test the diode with a multimeter (see attachment). Unless you have a scope that's pretty much it. You could test it for a short, but that requires you to desolder it from the board, and if you desolder it you might as well just replace it.
FDS6690AS should be the part number. You should be able to get it cheap at a local store or online and it's probably the problem.

P.S. Can you post pics of the board and the PQ41 mosfet?

[ktmmotocross]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

its 10A n-channel mosfet, part of stepdown convetrer for 1,2V rail. dont forget to chceck for short pq42

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

Do I have to remove PQ42 to check for the short

[ktmmotocross]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

just check for cross-short on it

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

sorry I'm new to mosfets. I've changed a few capacitors. What is a cross-short? Would I use the continuity test, diode test, or resistance check on it? That's sends current through it. Would I damage anything? Do I do the test with the motherboard off?

[reaper57]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

Continuity or resistance test should both get the job done, use which one you prefer. One probe on pin 4 one probe on 5. There should be no short. To test the diode positive probe on 1 and negative on 5. Then put the probe that was on 5 (negative) on 1 and the probe that was on 1 (positive) on 5. The fist should give you a short the second should give you no short.
Same should go for pq42
Board should be off.
No you are safe nothing will be damaged.
P.S. I'll let some one else tell you how to test the input and the output of the mosfet as I am very bad at reading schematics and I wasn't able to figure out the values you should get.

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

Thank you, I'll let you know what I find. Attached are some pictures. Let me know if you need closeups of any area? I found pq42 but was unable to find pq41?

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

"Continuity or resistance test should both get the job done, use which one you prefer. One probe on pin 4 one probe on 5. There should be no short. "

-- no short, meter reads open

"To test the diode positive probe on 1 and negative on 5. Then put the probe that was on 5 (negative) on 1 and the probe that was on 1 (positive) on 5. The fist should give you a short the second should give you no short."

Using continuity I get a short beep in each case and then the meter reads open. I measured the resistance for 1 and 5: --> 92 ohms, and 5 to 1 --> 142 ohms. Are these normal?

[cyberhack]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

Here this will help

[lmcancu]

Re: HP DV6-2064CA will only power up if its off for about 5 to 10 minutes

Thanks Cyber. I checked PQ59 and PQ54 which also use FDS6690AS. The diode test seems fine: ~ 167 ohms from 1 to 5, and open between 5 and 1. Can I safely assume that PQ41 is bad? i.e. the diode protection is shot? I still can't find PQ42? This is a caspian board and not Griffin maybe the schematic is a little different?